$(document).ready(function(){
/**
 * 粒子动画
 */
let resizeReset = function() {
    w = canvasBody.width = window.innerWidth;
    h = canvasBody.height = window.innerHeight;
}

const opts = {
    particleColor: "rgb(200,200,200)",
    lineColor: "rgb(200,200,200)",
    particleAmount: 50,
    defaultSpeed: 1,
    variantSpeed: 1,
    defaultRadius: 2,
    variantRadius: 2,
    linkRadius: 200,
};

window.addEventListener("resize", function(){
    deBouncer();
});

let deBouncer = function() {
    clearTimeout(tid);
    tid = setTimeout(function() {
        resizeReset();
    }, delay);
};

let checkDistance = function(x1, y1, x2, y2){
    return Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2));
};

let linkPoints = function(point1, hubs){
    for (let i = 0; i < hubs.length; i++) {
        let distance = checkDistance(point1.x, point1.y, hubs[i].x, hubs[i].y);
        let opacity = 1 - distance / opts.linkRadius;
        if (opacity > 0) {
            drawArea.lineWidth = 0.5;
            drawArea.strokeStyle = `rgba(${rgb[0]}, ${rgb[1]}, ${rgb[2]}, ${opacity})`;
            drawArea.beginPath();
            drawArea.moveTo(point1.x, point1.y);
            drawArea.lineTo(hubs[i].x, hubs[i].y);
            drawArea.closePath();
            drawArea.stroke();
        }
    }
}

Particle = function(xPos, yPos){
    this.x = Math.random() * w;
    this.y = Math.random() * h;
    this.speed = opts.defaultSpeed + Math.random() * opts.variantSpeed;
    this.directionAngle = Math.floor(Math.random() * 360);
    this.color = opts.particleColor;
    this.radius = opts.defaultRadius + Math.random() * opts. variantRadius;
    this.vector = {
        x: Math.cos(this.directionAngle) * this.speed,
        y: Math.sin(this.directionAngle) * this.speed
    };
    this.update = function(){
        this.border();
        this.x += this.vector.x;
        this.y += this.vector.y;
    };
    this.border = function(){
        if (this.x >= w || this.x <= 0) {
            this.vector.x *= -1;
        }
        if (this.y >= h || this.y <= 0) {
            this.vector.y *= -1;
        }
        if (this.x > w) this.x = w;
        if (this.y > h) this.y = h;
        if (this.x < 0) this.x = 0;
        if (this.y < 0) this.y = 0;
    };
    this.draw = function(){
        drawArea.beginPath();
        drawArea.arc(this.x, this.y, this.radius, 0, Math.PI*2);
        drawArea.closePath();
        drawArea.fillStyle = this.color;
        drawArea.fill();
    };
};

function setup(){
    particles = [];
    resizeReset();
    for (let i = 0; i < opts.particleAmount; i++){
        particles.push( new Particle() );
    }
    window.requestAnimationFrame(loop);
}

function loop(){
    window.requestAnimationFrame(loop);
    drawArea.clearRect(0,0,w,h);
    for (let i = 0; i < particles.length; i++){
        particles[i].update();
        particles[i].draw();
    }
    for (let i = 0; i < particles.length; i++){
        linkPoints(particles[i], particles);
    }
}

const canvasBody = document.getElementById("canvas"),
    drawArea = canvasBody.getContext("2d");
let delay = 200, tid,
    rgb = opts.lineColor.match(/\d+/g);
resizeReset();
setup();
});
document.getElementById("loginlink").addEventListener("click", function(event) {
    event.preventDefault(); // Prevent default link behavior

    // Simulate form submission by triggering submit event on the form
    document.getElementById("loginform").dispatchEvent(new Event("submit"));
});
document.getElementById("loginform").addEventListener("submit", function(event) {
    event.preventDefault(); // Prevent form submission

    // Get the username and password input values
    var username = document.getElementById("username").value;
    var password = document.getElementById("password").value;

    // Check if username and password are empty
    if (!username) {
        alert("未填写用户名");
        return;
    }
    if (!password) {
        alert("未填写密码");
        return;
    }
    // Check if username and password are correct
    if (username === "123" && password === "123") {
        // Redirect to the dashboard or any other page
        window.location.href = "index.html";
    } else {
        // Show error message using browser's alert
        alert("用户名或密码错误");
    }
});
